<template>
  <div class="list-footer" v-show="seleted > 0">
    <label>
      <input type="checkbox" v-model="isAll" />
    </label>
    <span
      ><span>已完成{{ totalSeleted }}</span> / 全部{{ seleted }}</span
    >
    <button class="btn" :class="className" @click="clearAllTodo">
      {{ itemBtn }}已选择
    </button>
  </div>
</template>

<script>
export default {
  name: "ListFooter",
  //   props: ["items"],
  props: {
    items: Array,
    itemBtn: String,
    className: {
      type: String,
      default: "btn-danger",
    },
  },
  computed: {
    seleted() {
      return this.items.length;
    },
    totalSeleted() {
      // previousValue 是第二个参数的初始化值，currentValue是从数组遍历出来的每一个元素
      /* return this.todos.reduce((previousValue, currentValue) => {
        return previousValue + (currentValue.done === true ? 1 : 0);
      }, 0); */
      // 简写
      return this.items.reduce(
        (previousValue, currentValue) =>
          previousValue + (currentValue.seleted === true ? 1 : 0),
        0
      );
    },
    isAll: {
      get() {
        return this.seleted === this.totalSeleted && this.seleted > 0;
      },
      set(value) {
        this.$emit("changeAllDone", value);
      },
    },
  },
  methods: {
    clearAllTodo() {
      this.$emit("clearAllTodo");
    },
  },
};
</script>

<style scoped>
.list-footer {
  height: 40px;
  line-height: 40px;
  padding-left: 6px;
  margin-top: 5px;
}

.list-footer label {
  display: inline-block;
  margin-right: 20px;
  cursor: pointer;
}

.list-footer label input {
  position: relative;
  top: -1px;
  vertical-align: middle;
  margin-right: 5px;
}

.list-footer button {
  float: right;
  margin-top: 5px;
}
.btn {
  /* display: inline-block; */
  padding: 4px 12px;
  margin-bottom: 0;
  font-size: 14px;
  line-height: 20px;
  text-align: center;
  vertical-align: middle;
  cursor: pointer;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, 0.2),
    0 1px 2px rgba(0, 0, 0, 0.05);
  border-radius: 4px;
}

.btn-danger {
  color: #fff;
  background-color: #da4f49;
  border: 1px solid #bd362f;
}
.btn-edit {
  color: #fff;
  background-color: skyblue;
  border: 1px solid rgb(85, 167, 199);
  margin-right: 3px;
}

.btn-danger:hover {
  color: #fff;
  background-color: #bd362f;
}

.btn:focus {
  outline: none;
}
</style>